Water-based microemulsions of a triazole fungicide

Abstract

Clear, stable, efficacious, aqueous microemulsions of an active triazole fungicide, e.g. penconazole, optionally with another agriculturally active chemical, are provided herein. The aqueous microemulsions are obtained by providing an inert matrix composition comprising a defined mixture of nonionic surfactants, including a C6-C18 alkylpyrrolidone, e.g. octylpyrrolidone, an alkylphenol ethoxylated alcohol having an HLB>/=6, preferably 10-20, e.g. nonylphenol ethoxylated alcohol with 9 EOs, and an anionic surfactant selected from a salt of dodecyl sulfate, dodecylbenzene sulfonate, dodecyltoluene sulfonate and lignin sulfonate, preferably sodium dodecyl sulfate, and water, optionally with a C1-C4 alkylpyrrolidone, e.g. N-methylpyrrolidone, and water. The inert matrix composition is admixed with a triazole fungicide, present in a C1-C4 alkylpyrrolidone, if not already present in the inert matrix composition, to form a microemulsion concentrate. Upon dilution with water, a stable, aqueous microemulsion is formed characterized by having a high loading of triazole fungicide e.g. 1-25% (before dilution), preferably about 14%.

What is claimed is: 
     
       1. An inert matrix composition for forming a clear, efficacious aqueous microemulsion upon admixture with a predetermined amount of a triazole fungicide and dilution water, which is stable at or below room temperature for an extended period of time, consisting essentially of: (i) a predetermined mixture of nonionic surfactants comprising:   (a) about 5-30% of a C 6  -C 18  alkylpyrrolidone;   (b) about 5-30% of an alkyl phenol ethoxylated alcohol with an HLB ≧6; and   an anionic surfactant comprising: (a') a metal salt of dodecylsulfate, dodecylbenzene sulfonate, dodecyltoluene sulfonate or lignin sulfonate, and     (iii) about 5-40% water;   (iv) up to 60% by weight of an N-alkyl(C 1  -C 4 )pyrrolidone; by weight of the composition.     
     
     
       2. An inert matrix composition according to claim 1 wherein (b) is a nonylphenol ethoxylated alcohol with 9 ethylene oxide groups. 
     
     
       3. An inert matrix composition according to claim 1 in which (a') is sodium dodecyl sulfate. 
     
     
       4. An inert matrix composition according to claim 1 in which the weight ratio of (a):(b):(a') is about 1: 1: 1. 
     
     
       5. An inert matrix composition according to claim 1 in which said N-alkyl(C 1  -C 4 )pyrrolidone is N-methylpyrrolidone. 
     
     
       6. A two-part microemulsion system for forming a clear, efficacious, aqueous microemulsion of a triazole fungicide by admixture of the respective parts of said system, and dilution water, which is stable at or below room temperature for an extended period of time, consisting essentially of: (i) as the first part, the inert matrix composition of claim 1, and   (ii) as the second part, a triazole fungicide, optionally including another active agricultural ingredient, selected from agricultural fertilizers, nutrients, plant growth accelerants, herbicides, plant growth controlling chemicals, insecticides, bactericides, fungicides, nematocides and fumigants; wherein, optionally, said system includes up to 60% by weight of an N-alkyl(C 1  -C 4 )pyrrolidone as cosolvent.     
     
     
       7. A system according to claim 6 in which said N-alkyl(C 1  -C 4 )pyrrolidone is present in an amount of up to 60% in the first part of said system. 
     
     
       8. A microemulsion concentrate for forming a clear, efficacious aqueous microemulsion of a triazole fungicide upon dilution with water, which is stable at or below room temperature for an extended period of time, consisting essentially of: about 5-30% of a C 6  -C 18  alkylpyrrolidone,   about 5-30% of an alkyl phenol ethoxylated alcohol having an HLB≧6,   about 5-30% of a metal salt of dodecyl sulfate, dodecylbenzene sulfonate, dodecyltoluene sulfonate or lignin sulfonate,   about 0-60% of an N-alkyl(C 1  -C 4 )pyrrolidone, and about 1-25% of a triazole fungicide, by weight of said concentrate.     
     
     
       9. A microemulsion concentrate according to claim 8 wherein said N-alkyl(C 1  -C 4 )pyrrolidone is N-methylpyrrolidone which is present in an amount of about 5-60%. 
     
     
       10. A microemulsion concentrate according to claim 8 in which said triazole fungicide is penconazole. 
     
     
       11. A clear, efficacious, aqueous microemulsion of a triazole fungicide which is stable at or below room temperature for an extended period of time consisting essentially of the microemulsion concentrate of claim 8 diluted up to 200 times with water. 
     
     
       12. An aqueous microemulsion comprising about 0.5-20 parts of the microemulsion concentrate of claim 8, and about 80-99.5 parts of water. 
     
     
       13. An aqueous microemulsion according to claim 11 which includes up to about 60% of an N-alkyl (C 1  -C 4 )pyrrolidone. 
     
     
       14. An aqueous microemulsion according to claim 13 wherein said N-alkyl(C 1  -C 4 )pyrrolidone is N-methylpyrrolidone. 
     
     
       15. An aqueous microemulsion according to claim 11 comprising: about 0.07% octylpyrrolidone,   about 0.07% nonyl phenol ethoxylated alcohol with 9 EOs,   about 0.07% sodium dodecyl sulfate,   about 0.07% N-methylpyrrolidone,   about 0.05% penconazole, and   about 99.7% water.